Process of enameling metal



UNITED STA -rEs P T NT OFFICE.

JOHN BOSTON, onFoI-I oAeo, ILLINOIS.

PROCESS or s A sumo ETAL.

srnemmncpmn forming part er Letters Patent No. c 974, dated June a, 1897. y Application filed June I, 1896. Serial'No. 593,885. (llo specimens.)

To all whomi't mag concern.-

.Be it known that 1, JOHN BOSTON, a citizen of the United States, residing. at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in the Process of Enameling Metal, of which the following is a specification.

The present invention relates to that class I of processes by which articles of iron, steel,

. p eces or scales.

nuity of the enamel itself is broken it will fall off.

Thc'principal objectof the present invention is to prevent this peeling 'oii of the enamel, andthis object I accomplish iupart by preventing oxidationof the surface of the article which it covers and in part by making the enamel itself elastic to such a degree that it is not frangible, but not to such. a degree that its elasticity is'apparent to the touch.

Each of these expedients has its own virtues and each isindependent-of the other, and

' while I prefer to use both of them, stillI desire to have it understood that I reserve to myself the exclusive right to use-either of them alone. 1 r

I Auo'ther'object of the invention is to pro vide an enamel that will take a higher polish than any of which I was aware prior to making the present invention.

To these ends the invention consists in the 'features of novelty that are particularlypointed out in the claims hereinafter.

In order to accomplish the several objects of my invention, the surface of the article to be enameled is first thoroughly cleansed. It is then dipped in a weak solution of aluminium acetate, after which it is placed in an oven and steamed for, say, ten or fifteen minutes. The temperature of this oven'is preferably about 212 Fahrenheit, and the the ace-tic acid and leaving the surface of the article completely covered by an aluminic coating. I am not prepared to state whether the aluminium contained in this coating exists in the metallic state or in a compound. After evaporating the acetic acid all loose steam is generated from water contained in a vessel which is placed in the. oven. This. decomposes the weak acetate, evaporating particles of the aluminic coating are removed from the surface of the article, and this may be done by wiping or rubbing the article with a cloth. The first coat of liquid enamel l1 iaint) is ihen applied in the usual way.

My invention in its broadest aspect is not limited to the use of an enamel made up of any particular ingredients, but I prefer to use a mixture of one hundred pounds of asphaltum, twenty-five quarts of boiled linseedoil,'and seventy-five quarts of kerosene-oil. The article with the first coat applied is then baked in the usual way-that is to say, it is placed in an oven heated either by steam or hot air to a temperature of, say, 375 Fahrenheit and there allowed to remain, say, one,

hour. The article is then polished. The second and succeeding coats of enamel may be applied in the same way, but I prefer to bake the second coat in an oven containing a quantityof sodium chlorid. If the air in the oven is dry, water is. added to the sodium chlorid.

It is my theory that more or less of the sodium chlorid is taken up by the atmosphere of the oven, penetrates the enamel, and combines to a greater or less extent with some of the aluminiumin the coating with which the article was previously covered, forming sodium aluminate. Whether this theory be sodium chlorid is used as described the enamel is fixed to the metal more securely, is more elastic and tenacious, and is capable of taking a higher polish than when the sodium chlorid is not used.

Having thus described my invention, the

following is what I claim as. new therein and desire to secure by Letters Patent:

true or not, it is undeniable that when the 1. The process of preparing an articlefor receiving a coating of enamel or paint, which consists in treating it with a solutiouof aluminium acetate, and then decomposing the lcetate c t aluminium by means of heat and noisture, leaving the article covered with an tluminic coating, substantially as set forth. -2. The process of preparing an article for 'eceiving a coating of enamel or paint, which :onsists in treating it with a solution of alu: ninium acetate,thendecomposing the acetate )f aluminium by meansof heat and moisture, caving the article covered with analuminic :oating, and then removing from the article he loose particles of the aluminic coating, vubstantially asset forth.' v

3. The process of enameling articles of netal, which consists in treating the article vith a solution of aluminium acetate, then lecomposin'g the acetate-of aluminium by neans of heat and moisture, leaving the ariclecoveredwith an aluminic coating, then applying tothe article a coat of liquid enamel- (paint) and then: baking the article and its coat, substantially as set forth.

4. The process of euamelingarticles oat metal, which consists in treating ,the article with a solution of aluminium acetate, then decomposing the acetate of aluminium by means of heat and moisture, leaving the article covered with an aluminic coating, then applying to the article a coat of liquid enamel (paint), then baking the aticle and its'coat in an oven containing chlorid' of sodium, and then polishing the coat, s1 .bst antially as set forth. A I

v JOHN BOSTON,

Witnesses:

- LOUIS G. SCHUMACHER, A-ucu'sr. KOEPPEN. 

